With the developments and applications of electronic products, there has been increasing demand for flat panel displays that consume less electric power and occupy less space. Among flat panel displays, organic light-emitting diode (OLED) displays are self-emitting, and highly luminous, with wider viewing angles, faster responses, and simple fabrication processes, making them the industry display of choice.
OLED displays are usually categorized into passive matrix OLED (PMOLED) displays and active matrix OLED (AMOLED) displays. The AMOLED display employs TFTs (thin film transistors) and storage capacitors to control the brightness and grayscale of the OLED display.
Generally, for an AMOLED display, compensation is required to ensure the stable performance of the luminance and color of the display. An AMOLED display usually has scan lines, data lines, and a pixel array connected to the scan lines and the data lines with each pixel having an OLED, and one or more compensation circuits connected to each pixel. In operation, a plurality of scan signals is provided sequentially to the scan lines such that, within a scan duration of the scan signals, a data signal transmitted to one of the pixels through the corresponding data line is written to the pixel, and compensation is also performed with the compensation circuits within the same scan duration in which the data is written to the pixel. Referring to FIG. 5, three of the scan signals, S(n−1), S(n) and S(n+1), and one of the data signal, D(k), are illustrated. Each of the scan signals S(n−1), S(n) and S(n+1) has a pulse with a pulse width defining the scan duration Ts. The data signal D(k) includes a stream of data pulses including Dn−1, Dn, Dn+1, . . . to be written to the pixels of different pixel rows in response to the scan signals S(n−1), S(n) and S(n+1), . . . , respectively. The stream of data pulses defines a period τ that is the same as the scan duration Ts. As shown in FIG. 5, within the scan duration Ts, the compensation with a compensation duration TC and the gate scan with a scan time Tg are performed.
Due to the requirement of high resolution and high frame rate of the display, the scan duration Ts is greatly reduced. For example, for a 120 Hz full-high-definition (FHD) OLED display, the average scan duration Ts is about 7.7 μs. The higher the resolution and the frame rate, the shorter the scan duration Ts. A shorter scan duration Ts requires a shorter compensation duration Tc for the compensation procedure. However, if the scan duration Ts becomes too short, it may be insufficient for the compensation procedure.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.